A six-port circuit is a kind of circuit which is often used in, for example, wireless communication systems, particularly in the microwave range. A six-port circuit has two input ports and four output ports, and produces at each of its four output ports a signal which is a composite of the signals applied at the input ports, in which composite signal the phase difference between the input signals comprised in the composite signal differs between the output ports. Usually, the phase difference varies in “steps” of 90 degrees, so that at the four output ports, the following phase differences between the signals applied at the input ports at output ports can be accessed or obtained: 0 degrees, 90 degrees, 180 degrees and 270 degrees.
A conventional six-port circuit comprises a number of so called Wilkinson power splitters and 90 degree hybrid couplers, which leads to a large circuit which needs to be implemented as, for example, microstrip or strip line solutions on a substrate.